Buggy code:
public class SpatialFeedbackController implements FeedbackControllerInterface { private final YoVariableRegistry registry ; private final BooleanYoVariable isEnabled ; private final YoFramePoint yoDesiredPosition ; private final YoFramePoint yoCurrentPosition ; private final YoFrameVector yoDesiredLinearVelocity ; private final YoFrameVector yoCurrentLinearVelocity ; private final YoFrameVector yoFeedForwardLinearAcceleration ; private final YoFrameVector yoDesiredLinearAcceleration ; private final YoFrameVector yoAchievedLinearAcceleration ; private final YoFrameQuaternion yoDesiredOrientation ; private final YoFrameQuaternion yoCurrentOrientation ; private final YoFrameVector yoDesiredRotationVector ; private final YoFrameVector yoCurrentRotationVector ; private final YoFrameVector yoDesiredAngularVelocity ; private final YoFrameVector yoCurrentAngularVelocity ; private final YoFrameVector yoFeedForwardAngularAcceleration ; private final YoFrameVector yoDesiredAngularAcceleration ; private final YoFrameVector yoAchievedAngularAcceleration ; private final SpatialAccelerationVector endEffectorAchievedAcceleration = new SpatialAccelerationVector ( ) ; private final FrameVector achievedAngularAcceleration = new FrameVector ( ) ; private final FrameVector achievedLinearAcceleration = new FrameVector ( ) ; private final FramePoint tempPosition = new FramePoint ( ) ; private final FrameVector tempLinearVelocity = new FrameVector ( ) ; private final FrameVector feedForwardLinearAcceleration = new FrameVector ( ) ; private final FrameVector desiredLinearAcceleration = new FrameVector ( ) ; private final FrameOrientation tempOrientation = new FrameOrientation ( ) ; private final FrameVector tempAngularVelocity = new FrameVector ( ) ; private final FrameVector feedForwardAngularAcceleration = new FrameVector ( ) ; private final FrameVector desiredAngularAcceleration = new FrameVector ( ) ; private final SpatialAccelerationVector desiredSpatialAcceleration = new SpatialAccelerationVector ( ) ; private final AxisAngle4d tempAxisAngle = new AxisAngle4d ( ) ; private final SpatialAccelerationCommand output = new SpatialAccelerationCommand ( ) ; private final BodyFixedPointSpatialAccelerationControlModule accelerationControlModule ; private final SpatialAccelerationCalculator spatialAccelerationCalculator ; private RigidBody base ; private final RigidBody endEffector ; private final ReferenceFrame endEffectorFrame ; public SpatialFeedbackController ( RigidBody endEffector , WholeBodyControlCoreToolbox toolbox , FeedbackControllerToolbox feedbackControllerToolbox , YoVariableRegistry parentRegistry ) { } public void submitFeedbackControlCommand ( SpatialFeedbackControlCommand command ) { } @ Override public void setEnabled ( boolean isEnabled ) { } @ Override public void initialize ( ) { } @ Override public void compute ( ) { } private void updatePositionVisualization ( ) { <START_BUG> desiredSpatialAcceleration . getAngularPart ( desiredLinearAcceleration ) ; <END_BUG> yoDesiredLinearAcceleration . setAndMatchFrame ( desiredLinearAcceleration ) ; tempPosition . setToZero ( accelerationControlModule . getTrackingFrame ( ) ) ; yoCurrentPosition . setAndMatchFrame ( tempPosition ) ; accelerationControlModule . getEndEffectorCurrentLinearVelocity ( tempLinearVelocity ) ; yoCurrentLinearVelocity . setAndMatchFrame ( tempLinearVelocity ) ; } private void updateOrientationVisualization ( ) { } public void computeAchievedAcceleration ( ) { } @ Override public boolean isEnabled ( ) { } @ Override public SpatialAccelerationCommand getOutput ( ) { } }

Fix:
desiredSpatialAcceleration . getLinearPart ( desiredLinearAcceleration ) ;